Seed coating composition

ABSTRACT

Composition for treating seeds comprising an aqueous emulsion of a substantially water-soluble neutralized copolymer of an Alpha , Beta -unsaturated monocarboxylic acid and a lower alkyl acrylate and a crosslinked copolymer of vinyl acetate and a lower alkyl acrylate. These compositions enhance the germination of the seeds.

United States Patent 1 Graves 1 Jan. 2, 1973 [54] SEED COATINGCOMPOSITION [56] ReierencesClted [75] Inventor:' 'Thomas M. Graves,Richmond, UNITED STATES PATENTS l'f. Cal 3,545,129 12/1970 Schreiber etal. ..47/57,6 Assisnw g 'f' 6 3 compllly, San 3,598,565 8/1971 Graves..71 17 rancisco, a1 [22] Filed: Dec. 2, 1970 Primary Examiner--RobertE. Bagwill [2]]- pp No 94 559 Attorney-J. A. Buchanan, Jr. et a1.

' Related US. Application Data [57] ABSTRACT 1 Division Of y 1968,Composition for treating seeds comprising an aqueous emulsion of asubstantially water-soluble neutralized copolymer of an a,B-unsaturatedmonocarboxylic acid [2%] (SI. 67114271, and a lower alkyl acrylate and acrosslinked 6 71/27 85 copolymer of vinyl acetate and a lower alkylacrylate.

These compositions enhance the germination of the seeds.

3 Claims, N0 Drawings SEED COATING COMPOSITION CROSS REFERENCE TORELATED APPLICATION This application is a division of application Ser.No. 748,617, filed July 30, 1968, now US. Pat. No. 3,598,565.

FIELD OF INVENTION This invention relates to a novel, water-soluble seedcoating composition comprising a homogeneous mixture of two copolymers.

INVENTION BACKGROUND It is common to treat seeds with hard resins toprotect the seed from damage during handling. Such coatings also affordthe advantages of protecting the seeds from pest attack and smoothingthe seed surface to make planting easier. In order to improve the seedgermination, or the germination rate, plant nutrients are incorporatedinto the hard resin coating. Pesticides may be incorporated to furtherprotect the seed from pest attack.

INVENTION DESCRIPTION A unique seed coating composition has now beendiscovered which not only provides a protective coating for the seed,but also enhances its germination rate and the viability of the emergingseedling. This enhancement occurs without incorporating plant nutrientsinto the coating composition.

The novel coating composition of this invention comprises an aqueousemulsion of two copolymers. One copolymer is a substantiallywater-soluble neutralized copolymer of an a,B-unsaturated monocarboxylicacid and a lower alkylacrylate. The mole proportion of neutralized acidto acrylate in these copolymers will usually range from 40:1 to about1:1, preferably 25:1 to 4:1.

The a,B-unsaturated monocarboxylic acid of the copolymer contains threeto about six carbon atoms. Such acids include acrylic acid,a-methylacrylic acid, crotonic acid, a-methylcrotonic acid and the like.Acrylic acid and a-methylacrylic acid are preferred. The loweralkylacrylate of the copolymer contains four to about carbon atoms; withthe acid (acrylate) moiety contributing three to about six carbon atomsto the total carbon number. Examples of such acrylates aremethylacrylate, ethylacrylate, isopropylacrylate,methyl-a-methylacrylate, ethyl-a-methylacrylate, amyl-a-methylacrylate,hexyl-a-methylacrylate, methylcrotonate, butylcrotonate,methyl-a-methylmoiety contributing three to about six carbon atoms tothe total carbon number. Examples of these acrylates are methylacrylate,ethylacrylate, hexylaerylate, methyl-a-methyl acrylate,butyl-a-methylacrylate, methylcrotonate, ethyl-a-methylcrotonate and thelike. The methyl esters of acrylic acid and a-methylacrylic acid arepreferred.

As used herein the term lower alkyl means alkyl of one to six carbonatoms.

The two copolymers usually comprise about 10 to 60 percent by weight ofthe aqueous emulsion. The weight ratio of the crosslinkedpolyvinylacetate copolymer to the a,B-unsaturated acid-acrylatecopolymer will be about 1:2 to about 1:10, preferably 1:3 to 1:5. Thecomposition of this invention also contains one or more nonionicemulsifiers in amounts normally ranging between 0.5 to 5 percent byweight of the composition. Typical nonionic emulsifiers are thepolyethenoxy ethers and esters such as the condensation products offatty acids, alcohols or phenolics with ethylene and/or propylene oxide;esters of fatty acids and polyols; condensation products of alkyleneoxides and thiols; polyoxyalkylene esters of phosphoric acid andpolyhydroxy compounds such as sucrose, dextrine and the like. Suchemulsifiers are described in Surface Active Agents and Detergents,Schwartz, Perry and Berch, Interscience (1958).

The emulsion may also contain pigments, pesticides 0 and otheradditives. Plant nutrients may also be added;

0 spraying or brushing. Alternatively, the seeds maybe crotonate and thelike. The lower alkyl esters of acrylic acid and a-methylacrylic acidare preferred.

The acid portion of the copolymer is neutralized with an alkaline earthmetal, alkali metal or ammonium base. After neutralization the copolymerwill have a pH in the range of about 5.5 to 8.5.

The second copolymer is a polyvinylacetate crosslinked with a smallamount of lower alkylacrylate. The amount of lower alkylacrylate in thiscrosslinked copolymer will usually be not greater than 25 percent byweight. Usually it will be about 0.3 to 5 percent by weight of thesecond copolymer.

The lower alkylacrylate of the second copolymer contains four to about10 carbon atoms; with the acid tumbled or dipped into the inventioncomposition. The thickness of the resulting seed coating will vary withthe type of seed. Usually it will range between about 0.001 and about 5mils, preferably 0.01 to 2 mils.

The coating of this invention has been used with a variety of seedsincluding com, peas, beans, wheat, sorghum, cotton, sunflower and othergrain seeds. The coatings on these seeds cause them to generallygerminate faster and enhance the seedling growth and viability.

EXAMPLES The compositions of this invention and their physiologicaleffects on seeds are illustrated by the following examples. Theseexamples are intended to illustrate the invention described herein andare not intended to limit it in any manner. Unless indicated otherwise,percentages are by weight.

EXAMPLE 1 A resin seed coating of this invention was prepared by mixing15.5 g. of a 40 percent aqueous emulsion of a copolymer comprising vinylacetate crosslinked with a small amount of lower alkyl methacrylate(sold under the name Nacrylic 25-2813) and 84.5 g. ofa 30 percentaqueous solution of a neutralized acrylic acid methyl methacrylatecopolymer (sold under the name Joneryl 85"). 3.88 g. of this mixture wasadded to 5.15 g. of an aqueous solution of l g. of N-(trichloromethylthio) tetrahydrophthalimide seed protectant (sold asOrthocide 75 Seed Protectant). The mixture was agitated for minutes witha creamy suspension resulting.

100 g. of seed corn was placed in a 16 oz. jar. 1 ml. of theabove-described resin seed coating was placed on top of the corn. Thebottle was sealed and swirled for 2 minutes. The seeds were spread outand allowed to dry for 5 minutes.

The resulting seed coating was uniform, non-dusty and had a thickness ofabout 0.2 ml. The coating was completely soluble in water.

The seeds were germinated in dishes lined with filter paper and alongwith comparison seeds treated only with the N-(trichloromethylthio)tetrahydrophthalimide seed protectant and water at the same rate.

The seeds were watered with ml. of water initially. At the end of 2 and5 days the hypocotyl and epicotyl growths were measured in millimetersand compared. Based on these measurements the resin treated seeds showedabout an 18 percent better growth than the comparison seeds after 2 daysand about a 31 percent better growth after 5 days.

The root systems were carefully clipped from each seed and weighed. Theresin treated seed clippings showed a weight increase of about 17percent after 5 days, over the comparison seed clippings.

EXAMPLE 2 100 g. of bean seeds was placed in a 16 oz. jar. 1 ml. of theresin seed coating of Example 1 was placed on top of the beans. Thebottle was scaled and swirled for 2 minutes. The seeds were spread outand allowed to dry for 5 minutes.

The resulting seed coating was uniform, non-dusty and had a thickness ofabout 0.4 ml. The coating was completely soluble in water. These beanseeds and comparison bean seeds were germinated as in Example 1. At theend of 2 and 5 days the root systems were measured in millimeters. Thesemeasurements showed the resin treated seeds had about 50 percent bettergrowth than the comparison seeds after 2 days and about 50 percentbetter growth after 5 days. The resin treated seed clippings showed aweight increase of about 47 percent after 5 days over the comparisonseed clippings.

EXAMPLE 3 g. of wheat seed was placed in a 16 oz. jar. 1 ml. of theresin seed coating of Example 1 was placed on top of the wheat. Thebottle was sealed and swirled for 2 minutes. The seeds were spread outand allowed to dry for 5 minutes. The resulting seed coating was uniformand had a thickness of about 0.05 ml. The coating was completely solublein water.

These seeds and comparison seeds were germinated as in Example 1. At theend of 5 and 10 days hypocotyl and epicotyl growths were measured inmillimeters. These measurements showed that the resin treated seeds hadabout 10 percent better growth than the comparison seeds after 5 daysand about 11 percent better th ter l0da s.

As w iw e ca dent to those skilled in the art, various modifications onthis invention can be made or followed, in the light of the foregoingdisclosure and discussion, without departing from the spirit or scope ofthe disclosure or from the scope of the following claims.

I claim:

1. A coated seed having a mixture comprising an aqueous emulsion of l) asubstantially water-soluble neutralized copolymer of an a,B-unsaturatedmonocarboxylic acid of three to about six carbon atoms and a lower alkylacrylate of four to about 10 carbon atoms, and (2) a crosslinkedcopolymer of vinyl acetate and a lower alkyl acrylate of four to about10 carbon atoms, the weight ratio of the crosslinked copolymer to thewater-soluble neutralized copolymer being in the range of about 1:2 toabout 1:10.

2. The coated seed of claim 1 in which the a,B-unsaturatedmonocarboxylic acid is acrylic acid or amethyl-acrylic acid, the loweralkyl acrylate of the substantially water-soluble copolymer is a loweralkyl ester of acrylic acid or a lower alkyl ester of a-methylacrylicacid and the lower alkyl acrylate of the crosslinked copolymer is themethyl ester of acrylic acid or the methyl ester of a-methylacrylicacid.

3. The coated seed of claim 1 wherein the seed coating is about 0.001 to5 mils thick.

2. The coated seed of claim 1 in which the Alpha , Beta -unsaturatedmonocarboxylic acid is acrylic acid or Alpha -methyl-acrylic acid, thelower alkyl acrylate of the substantially water-soluble copolymer is alower alkyl ester of acrylic acid or a lower alkyl ester of Alpha-methylacrylic acid and the lower alkyl acrylate of the crosslinkedcopolymer is the methyl ester of acrylic acid or the methyl ester ofAlpha -methylacrylic acid.
 3. The coated seed of claim 1 wherein theseed coating is about 0.001 to 5 mils thick. 10.